function setMenuLocation(anchor, menu) {	
	var mainMenu = document.getElementById("mainMenu");
	var _anchor = document.getElementById(anchor);
	var _menu = document.getElementById(menu);
	
	var top = topPos(mainMenu) + mainMenu.offsetHeight - 1;
	
	_menu.style.top = "" + top + "px";
	_menu.style.left = "" + leftPos(_anchor) + "px";	
	show(menu);	
}

function leftPos(obj) {
	var left = 0;
	
	do {
		left += obj.offsetLeft;
	} while(obj = obj.offsetParent);
	
	return left;
}


function topPos(obj) {
	var top = 0;
	
	do {
		top += obj.offsetTop;
	} while(obj = obj.offsetParent);
	
	return top;
}


function hide(menu) {
	document.getElementById(menu).style.visibility = "hidden";
}


function show(menu) {
	document.getElementById(menu).style.visibility = "visible";
}